The singular ability of immunoglobulin genes to hypermutate their variable regions, while permitting the generation of high-affinity antibodies against foreign antigens, poses a problem in terms of maintenance of immunological self-tolerance. Immunoglobulin gene hypermutation driven by a foreign antigen has the potential to generate antibodies that cross-react with self-components. Consequently...

Atherosclerotic lesions contain relatively large quantities of IgG. We have previously shown that both human and rabbit sera contain autoantibodies against epitopes of oxidized (Ox) low-density lipoprotein (LDL) and that LDL isolated from atherosclerotic lesions contains small amounts of tightly bound IgG. However, it is not known whether IgG isolated from atherosclerotic lesions recognizes epi...

The effects of the human and bovine LSF (derived from sera) as well as their purified fractions were studied on murine lymphocytes reactions indicated by blast transformation (BT) assay, mixed lymphocyte culture (MLC) and IgG synthesis. The results indicated that bovine lipid suppressor factor (LSF) has significant immunosuppressive activity on lymphocytes proliferation both in BT and MLC ...

The neonatal Fc receptor (FcRn) is a major regulator of IgG and albumin homeostasis systemically and in the kidneys. We investigated the role of FcRn in the development of immune complex-mediated glomerular disease in mice. C57Bl/6 mice immunized with the noncollagenous domain of the α3 chain of type IV collagen (α3NC1) developed albuminuria associated with granular capillary loop deposition of...

The biological activities of human IgG antibodies predominantly rely on a family of receptors for the Fc portion of IgG, FcγRs: FcγRI, FcγRIIA, FcγRIIB, FcγRIIC, FcγRIIIA, FcγRIIIB, FcRL5, FcRn, and TRIM21. All FcγRs bind IgG at the cell surface, except FcRn and TRIM21 that bind IgG once internalized. The affinity of FcγRs for IgG is determined by polymorphisms of human FcγRs and ranges from 2 ...

When pooled immunoglobulin G (IgG) from patients with multiple sclerosis (MS) was used to probe a human fetal spinal cord λgt 11 cDNA library, the IgG was found to bind to a predicted epitope of human mitochondrial ND4 sequence. To investigate the involvement of the ND4 as an autoantigen in MS, we determined the presence of specific antibody in the serum of MS patients and serum samples of...

A new signal amplification strategy based on simultaneous application of gold nanoparticles (AuNPs) and horseradish peroxidase (HRP) was employed to improve the sensitivity of an electrochemical immunoassay for detection of human IgG (hIgG), as a model antigenic protein. This immunoassay system was fabricated on magnetic carboxyl-functionalized multi-walled carbon nanotubes (COOH-MWCNT/Fe3...

Human cytomegalovirus (HCMV)-infected cells express a virus-encoded receptor that is able to bind the Fc part of IGG: Some basic binding properties of this Fc receptor (FcR) have been examined. The affinity constant (K(a)) for human IgG Fc fragment in its interaction with acetone-fixed, HCMV-infected human embryonic lung fibroblasts was estimated to be around 2 x 10(8) M(-1) and the number of b...

Immunoglobulins (Igs) are found thus far only to be produced by differentiated B lymphocytes. By immunohistochemistry analysis, in situ hybridization, and laser capture microdissection-assisted single-cell PCR, we demonstrate that human cancers of epithelial origin, including carcinomas of breast, colon, liver, lung, established epithelial cancer lines, as well as some normal lung tissues, also...

Studies for vaccine and human therapeutic Ab development in cynomolgus monkeys (cynos) are influenced by immune responses, with Ab responses playing a significant role in efficacy and immunogenicity. Understanding the nature of cyno humoral immune responses and characterizing the predominant cyno IgG types produced and the Fc-FcγR interactions could provide insight into the immunomodulatory eff...